The Research Of Application On The Mini-piles And Anchor Combined Support System In The Foundation Pit

The mini-piles and anchor combined support system is taking the advantages of mini-piles and anchor to support foundation pit, the support system is a new type of composite support mode which can control deformation in order to ensure the construction project go smoothly. The supporting system has the advantages of convenient construction, simple structure and flexible layout. Based on the foundation pit supporting of The Fourth Water Making co. LTD., the thesis analyzed the work mechanism of the combined support system, the construction methods and the designing characteristics. On the basis of the supporting system of foundation pit construction monitoring, using finite element analysis method, the thesis compared with the monitoring data and analyzed the force and deformation characteristics of the system. The conclusion that the combined support system can effectively control deformation and ensure the safety of the engineering construction is a form of combined support system which is worth of popularizing.This main work and research results of the thesis are as follows:(1) It set out the characteristics, structure, working mechanism and construction technology of the mini-piles and anchor combined support system. And then it analyzed the stress and deformation situation of the main component of the combined support system (micro-pile, anchor, top beam),also it expounded the working process of the combined supporting structure;(2) Based on the analysis about the engineering geology, hydrogeology and surrounding buildings of the project, the thesis formulated a detailed construction monitoring scheme and analyzed the monitoring results, giving the conclusion that the monitoring indicators are all within the scope of the permit and the combined support system used in actual engineering is feasible, safe and economic;(3) By using the finite element analysis software GeoStudio2007, the thesis established the pit modeling and analyzed the stress and deformation of the foundation pit and mini-piles, anchor’s axial force changes etc under different working conditions, and then it compared with the measured dates that depending on the project. The results showed that the theoretical analysis and monitoring results have good consistency.